Erythropoietin improves left ventricular function and coronary flow in an experimental model of ischemia-reperfusion injury

Remote ischemia per-conditioning (RPerC) has been demonstrated to have cardiac protection, but the underlying mechanism remains unclear. This study aimed to investigate the mechanism underlying cardiac protection of RPerC. Adult male Sprague–Dawley rats were used in this study. Cardiac ischemia/reperfusion (I/R) was induced by 30 min of occlusion and 3 h of reperfusion of the left anterior descending coronary artery. RPerC were performed by 5 min of occlusion of the right femoral artery followed by 5 min of reperfusion for three times during cardiac ischemia. The hemodynamics, left ventricular function, arrhythmia, and infarct area were measured. Protein expression levels of endothelial nitric oxide synthase (eNOS), inducible NOS (iNOS), protein kinase C-ε (PKCε), and PKCδ in the myocardium were assayed. During I/R, systolic artery pressure and left ventricular function were decreased, infarct area was increased, and arrhythmia score was increased (P < 0.05). However, changes of the above parameters were significantly attenuated in RPerC-treated rats compared with control rats (P < 0.05). The cardiac protective effects of RPerC were prevented by naloxone or glibenclamide. Also, RPerC increased the protein expression levels of eNOS, iNOS, PKCε, and PKCδ in the myocardium compared with control rats. These effects were blocked by naloxone, an opioid receptor antagonist, and glibenclamide, an ATP-sensitive K+ channel blocker (KATP). In summary, this study suggests that RPerC protects the heart against I/R injury through activation of opioid receptors and the NO–PKC–KATP channel signaling pathways.

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Targeting the Cx43 Carboxyl Terminal H2 Domain Preserves Left Ventricular Function Following Ischemia-Reperfusion Injury

10.1101/668509 ◽

2019 ◽

Author(s):

Jingbo Jiang ◽

Joseph A. Palatinus ◽

Huamei He ◽

Jegan Iyyathurai ◽

L. Jane Jourdan ◽

...

Keyword(s):

Amino Acid ◽

Reperfusion Injury ◽

Ventricular Function ◽

Ischemia Reperfusion Injury ◽

Contractile Function ◽

Ischemia Reperfusion ◽

Ischemic Injury ◽

Left Ventricular ◽

Therapeutic Peptide

ABSTRACTBackgroundαCT1 is a 25 amino acid therapeutic peptide incorporating the Zonula Occludens-1 (ZO-1)-binding domain of connexin43 (Cx43) that is currently in Phase III clinical testing for healing chronic skin wounds. In preclinical studies in mice, we reported that αCT1 reduces arrhythmias and improves ventricular function following cardiac injury, effects that were accompanied by increases in PKCε phosphorylation of Cx43 at serine 368 (pS368). In this study, we undertake a systematic characterization of the molecular mode-of-action of αCT1 in mitigating the effects of ischemia reperfusion injury on ventricular contractile function.Methods and ResultsTo determine the basis of αCT1-mediated increases in pS368 we undertook tandem mass spectrometry of reactants in an in vitro assay of PKCε phosphorylation, identifying an interaction between negatively charged amino acids in the αCT1 Asp-Asp-Leu-Glu-Iso sequence and positively charged lysines (Lys345, Lys346) in a short α-helical sequence (H2) within the Cx43 CT domain. In silico modeling provided further support of the specificity of this interaction, leading us to conclude that αCT1 has potential to directly interact with both Cx43 and ZO-1. Using surface plasmon resonance, thermal shift and phosphorylation assays, we characterized a series of αCT1 variant peptides, identifying sequences competent to interact with either ZO-1 PDZ2 or the Cx43 CT, but with limited or no ability to bind both polypeptides. Based on this analysis, it was found that only those peptides competent to interact with Cx43, but not ZO-1 alone, resulted in increased pS368 phosphorylation in vitro and in vivo. Moreover, in a mouse model of global ischemia reperfusion injury we determined that pre-ischemic infusion only with those peptides competent to bind Cx43 preserved left ventricular (LV) contractile function following injury. Interestingly, a short 9 amino acid (MW=1110) Cx43-binding variant of the original 25 amino acid αCT1 sequence demonstrated potent LV-protecting effects when infused either before or after ischemic injury.ConclusionsInteraction of αCT1 with the Cx43 CT, but not ZO-1 PDZ2, explains cardioprotection mediated by this therapeutic peptide. Pharmacophores targeting the Cx43 carboxyl terminus could provide a novel translational approach to preservation of ventricular function following ischemic injury.

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Chronic skeletal muscle ischemia preserves coronary flow in the ischemic rat heart

AJP Heart and Circulatory Physiology ◽

10.1152/ajpheart.00232.2011 ◽

2011 ◽

Vol 301 (4) ◽

pp. H1229-H1235 ◽

Cited By ~ 4

Author(s):

Varnavas C. Varnavas ◽

Konstantinos Kontaras ◽

Chryssoula Glava ◽

Christos D. Maniotis ◽

Michael Koutouzis ◽

...

Keyword(s):

Left Ventricular Function ◽

Infarct Size ◽

Ventricular Function ◽

Coronary Flow ◽

Ischemia Reperfusion ◽

Limb Ischemia ◽

Ventricular Myocardium ◽

Left Ventricular ◽

Hindlimb Ischemia ◽

Muscle Ischemia

Chronic skeletal muscle ischemia confers cytoprotection to the ventricular myocardium during infarction, but the underlying mechanisms remain unclear. Although neovascularization in the left ventricular myocardium has been proposed as a possible mechanism, the functional capacity of such vessels has not been studied. We examined the effects of chronic limb ischemia on infarct size, coronary blood flow, and left ventricular function after ischemia-reperfusion. Hindlimb ischemia was induced in 65 Wistar rats by excision of the left femoral artery, whereas 65 rats were sham operated. After 4 wk, myocardial infarction was generated by permanent coronary artery ligation. Infarct size was measured 24 h postligation. Left ventricular function was evaluated in isolated hearts after ischemia-reperfusion, 4 wk after limb ischemia. Neovascularization was assessed by immunohistochemistry, and coronary flow was measured under maximum vasodilatation at different perfusion pressures before and after coronary ligation. Infarct size was smaller after limb ischemia compared with controls (24.4 ± 8.1% vs. 46.2 ± 9.5% of the ventricle and 47.6 ± 8.7% vs. 80.1 ± 9.3% of the ischemic area, respectively). Indexes of left ventricular function at the end of reperfusion (divided by baseline values) were improved after limb ischemia (developed pressure: 0.68 ± 0.06 vs. 0.59 ± 0.05, P = 0.008; maximum +dP/d t: 0.70 ± 0.08 vs. 0.59 ± 0.04, P = 0.004; and maximum −dP/d t: 0.86 ± 0.14 vs. 0.72 ± 0.10, P = 0.041). Coronary vessel density was markedly higher ( P = 0.00021) in limb ischemic rats. In contrast to controls ( F = 5.65, P = 0.00182), where coronary flow decreased, it remained unchanged ( F = 1.36, P = 0.28) after ligation in limb ischemic rats. In conclusion, chronic hindlimb ischemia decreases infarct size and attenuates left ventricular dysfunction by increasing coronary collateral vessel density and blood flow.

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Heat Shock Protein 70 Gene Transfection Protects Mitochondrial and Ventricular Function Against Ischemia-Reperfusion Injury

Circulation ◽

10.1161/circ.104.suppl_1.i-303 ◽

2001 ◽

Vol 104 (suppl_1) ◽

Author(s):

Jay Jayakumar ◽

Ken Suzuki ◽

Ivan A. Sammut ◽

Ryszard T. Smolenski ◽

Mak Khan ◽

...

Keyword(s):

Heat Shock ◽

Heat Shock Protein ◽

Reperfusion Injury ◽

Ventricular Function ◽

Mitochondrial Function ◽

Heat Shock Protein 70 ◽

Ischemia Reperfusion Injury ◽

Ischemia Reperfusion ◽

Gene Transfection ◽

Left Ventricular

Background Upregulation of heat shock protein 70 (HSP70) is beneficial in cardioprotection against ischemia-reperfusion injury, but the mechanism of action is unclear. We studied the role of HSP70 overexpression through gene therapy on mitochondrial function and ventricular recovery in a protocol that mimics clinical donor heart preservation. Methods and Results Hemagglutinating virus of Japan (HVJ)-liposome technique was used to transfect isolated rat hearts via intracoronary infusion of either the HSP70 gene (HSP group, n=16) or no gene (CON group, n=16), which was heterotopically transplanted into recipient rats. Four days after surgery, hearts were either perfused on a Langendorff apparatus for 30 minutes at 37°C (preischemia studies [n=8/group]) or perfused for 30 minutes at 37°C, cardioplegically arrested for 4 hours at 4°C, and reperfused for 30 minutes at 37°C (postischemia studies [n=8/group]). Western blotting and immunohistochemistry confirmed HSP70 upregulation in the HSP group. Postischemic mitochondrial respiratory control indices (RCIs) were significantly better preserved in HSP than in CON hearts: NAD + -linked RCI values were 9.54±1.1 versus 10.62±0.46 before ischemia (NS) but 7.98±0.69 versus 1.28±0.15 after ischemia ( P <0.05), and FAD-linked RCI values were 6.87±0.88 versus 6.73±0.93 before ischemia (NS) but 4.26±0.41 versus 1.34±0.13 after ischemia ( P <0.05). Postischemic recovery of mechanical function was greater in HSP than in CON hearts: left ventricular developed pressure recovery was 72.4±6.4% versus 59.7±5.3% ( P <0.05), maximum dP/dt recovery was 77.9±6.6% versus 52.3±5.2% ( P <0.05), and minimum dP/dt recovery was 72.4±7.2% versus 54.8±6.9% ( P <0.05). Creatine kinase release in coronary effluent after reperfusion was 0.20±0.04 versus 0.34±0.06 IU · min −1 · g wet wt −1 ( P <0.05) in HSP versus in CON hearts. Conclusions HSP70 upregulation protects mitochondrial function after ischemia-reperfusion injury; this was associated with improved preservation of ventricular function. Protection of mitochondrial function may be important in the development of future cardioprotective strategies.

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Reducing Cardiac Injury during ST-Elevation Myocardial Infarction: A Reasoned Approach to a Multitarget Therapeutic Strategy

Journal of Clinical Medicine ◽

10.3390/jcm10132968 ◽

2021 ◽

Vol 10 (13) ◽

pp. 2968

Author(s):

Alessandro Bellis ◽

Giuseppe Di Gioia ◽

Ciro Mauro ◽

Costantino Mancusi ◽

Emanuele Barbato ◽

...

Keyword(s):

Myocardial Infarction ◽

Reperfusion Injury ◽

Therapeutic Strategy ◽

Ventricular Remodeling ◽

Ischemia Reperfusion Injury ◽

Ischemia Reperfusion ◽

Left Ventricular ◽

St Elevation Myocardial Infarction ◽

Ischemic Time ◽

St Elevation

The significant reduction in ‘ischemic time’ through capillary diffusion of primary percutaneous intervention (pPCI) has rendered myocardial-ischemia reperfusion injury (MIRI) prevention a major issue in order to improve the prognosis of ST elevation myocardial infarction (STEMI) patients. In fact, while the ischemic damage increases with the severity and the duration of blood flow reduction, reperfusion injury reaches its maximum with a moderate amount of ischemic injury. MIRI leads to the development of post-STEMI left ventricular remodeling (post-STEMI LVR), thereby increasing the risk of arrhythmias and heart failure. Single pharmacological and mechanical interventions have shown some benefits, but have not satisfactorily reduced mortality. Therefore, a multitarget therapeutic strategy is needed, but no univocal indications have come from the clinical trials performed so far. On the basis of the results of the consistent clinical studies analyzed in this review, we try to design a randomized clinical trial aimed at evaluating the effects of a reasoned multitarget therapeutic strategy on the prevention of post-STEMI LVR. In fact, we believe that the correct timing of pharmacological and mechanical intervention application, according to their specific ability to interfere with survival pathways, may significantly reduce the incidence of post-STEMI LVR and thus improve patient prognosis.

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